Patents by Inventor Hidehiko Kandou

Hidehiko Kandou has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Laser drive unit and information recording/reproducing apparatus
    Patent number: 6636472
    Abstract: A laser drive (LD) unit 1 according to the present invention is provided with a laser drive waveform controller 6, into which information for setting the laser drive is entered from a controller 2, for generating a laser drive waveform on the basis of that information and supplying an indicated amperage; an LD current setting unit 7 for setting a laser drive current matching the indicated amperage; an LD current output unit 8 for varying the laser drive current on the basis of the laser drive waveform and supplying the current so varied to a laser diode 3; and a current setting corrector 9, into which a monitor signal obtained at the time of monitoring the laser beam emission from the laser diode 3 is monitored, for correcting the laser drive current set by the current setting unit 7 by using that monitor signal to adjust the power of the laser diode 3. The laser drive waveform controller 6, current setting unit 7, current output unit 8 and current setting corrector 9 are formed on the same substrate.
    Type: Grant
    Filed: May 22, 2002
    Date of Patent: October 21, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Masaaki Kurebayashi, Akihiro Asada, Toshimitsu Kaku, Hideo Oonuki, Takashi Hoshino, Hidehiko Kandou
  • Laser drive unit and information recording/reproducing apparatus
    Patent number: 6487154
    Abstract: A laser drive (LD) unit 1 according to the present invention is provided with a laser drive waveform controller 6, into which information for setting the laser drive is entered from a controller 2, for generating a laser drive waveform on the basis of that information and supplying an indicated amperage; an LD current setting unit 7 for setting a laser drive current matching the indicated amperage; an LD current output unit 8 for varying the laser drive current on the basis of the laser drive waveform and supplying the current so varied to a laser diode 3; and a current setting corrector 9, into which a monitor signal obtained at the time of monitoring the laser beam emission from the laser diode 3 is monitored, for correcting the laser drive current set by the current setting unit 7 by using that monitor signal to adjust the power of the laser diode 3. The laser drive waveform controller 6, current setting unit 7, current output unit 8 and current setting corrector 9 are formed on the same substrate.
    Type: Grant
    Filed: January 25, 2000
    Date of Patent: November 26, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Masaaki Kurebayashi, Akihiro Asada, Toshimitsu Kaku, Hideo Oonuki, Takashi Hoshino, Hidehiko Kandou
  • Laser drive unit and information recording/reproducing apparatus
    Publication number: 20020136120
    Abstract: A laser drive (LD) unit 1 according to the present invention is provided with a laser drive waveform controller 6, into which information for setting the laser drive is entered from a controller 2, for generating a laser drive waveform on the basis of that information and supplying an indicated amperage; an LD current setting unit 7 for setting a laser drive current matching the indicated amperage; an LD current output unit 8 for varying the laser drive current on the basis of the laser drive waveform and supplying the current so varied to a laser diode 3; and a current setting corrector 9, into which a monitor signal obtained at the time of monitoring the laser beam emission from the laser diode 3 is monitored, for correcting the laser drive current set by the current setting unit 7 by using that monitor signal to adjust the power of the laser diode 3. The laser drive waveform controller 6, current setting unit 7, current output unit 8 and current setting corrector 9 are formed on the same substrate.
    Type: Application
    Filed: May 22, 2002
    Publication date: September 26, 2002
    Applicant: Hltachi, Ltd.
    Inventors: Masaaki Kurebayashi, Akhiro Asada, Toshimitsu Kaku, Hideo Oonuki, Takashi Hoshino, Hidehiko Kandou